A high-ranking security official, speaking to The Associated Press on condition of anonymity because he was not authorised to comment on an ongoing investigation, said the suspects were both Iraqi-born British subjects in their 20s.
The two were arrested last night by coast guard officers near the port of the northeastern Greek city of Alexandroupolis. They were driving a trailer.
A coast guard spokesman also confirmed the arrests but would not provide further information.
The suspects were carrying more than a dozen guns and well over 20,000 bullets, the security official says. The two are not on any terrorist or criminal database.